7 ideas
| 17744 | De Morgan started the study of relations and their properties [De Morgan, by Walicki] |
| Full Idea: De Morgan started the sustained interest in the study of relations and their properties. | |
| From: report of Augustus De Morgan (On the Syllogism IV [1859]) by Michal Walicki - Introduction to Mathematical Logic History D.1.1 |
| 13501 | De Morgan found inferences involving relations, which eluded Aristotle's syllogistic [De Morgan, by Hart,WD] |
| Full Idea: There was a prejudice against relations (in favour of properties) but De Morgan and others that impeccable inferences turn on relations and elude Aristotle's syllogistic. Thus: All horses are animals. Hence, all heads of horses are heads of animals. | |
| From: report of Augustus De Morgan (On the Syllogism IV [1859]) by William D. Hart - The Evolution of Logic 4 | |
| A reaction: This is actually an early example of modern analytic philosophy in action. You start with the inferences, and then work back to the ontology and the definition of concepts. But in pinning down such concepts, do we miss their full meaning? |
| 12354 | A 'categorial' property is had by virtue of being or having an item from a category [Wedin] |
| Full Idea: A 'categorial' property is a property something has by virtue of being or having an item from one of the categories. | |
| From: Michael V. Wedin (Aristotle's Theory of Substance [2000], V.5) | |
| A reaction: I deny that these are 'properties'. A thing is categorised according to its properties. To denote the category as a further property is the route to madness (well, to a regress). |
| 12358 | Substance is a principle and a kind of cause [Wedin] |
| Full Idea: Substance [ousia] is a principle [arché] and a kind of cause [aitia]. | |
| From: Michael V. Wedin (Aristotle's Theory of Substance [2000], 1041a09) | |
| A reaction: The fact that substance is a cause is also the reason why substance is the ultimate explanation. It is here that I take the word 'power' to capture best what Aristotle has in mind. |
| 12346 | Form explains why some matter is of a certain kind, and that is explanatory bedrock [Wedin] |
| Full Idea: The form of a thing (of a given kind) explains why certain matter constitutes a thing of that kind, and with this, Aristotle holds, we have reached explanatory bedrock. | |
| From: Michael V. Wedin (Aristotle's Theory of Substance [2000], Intro) | |
| A reaction: We must explain an individual tiger which is unusually docile. It must have an individual form which makes it a tiger, but also an individual form which makes it docile. |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |